Method for recycling positive electrode material of waste battery

Abstract

The invention discloses a waste battery positive electrode material recovery method, which comprises: mixing a waste battery positive electrode material and a sulfuric acid solution to obtain a slurry, the waste battery positive electrode material comprising at least one of Ni < 3 + >, Co < 3 + > and Mn < 3 + >; the slurry and cobalt hydroxide acid leaching residues are mixed, a first leaching reaction is carried out, so that first leaching liquid and first leaching residues are obtained, and the cobalt hydroxide acid leaching residues comprise cobalt sulfide; the first leaching solution and iron powder are mixed, a second leaching reaction is conducted, so that a second leaching solution and second leaching residues are obtained, and the first leaching solution comprises copper ions; and the second leaching solution and nickel cobalt hydroxide acid leaching residues are mixed, a third leaching reaction is carried out, so that a recovery solution and third leaching residues are obtained, and the nickel cobalt hydroxide acid leaching residues comprise at least one of MnO2, Mn3O4 and MnO (OH). The cobalt hydroxide acid leaching residues and the nickel cobalt hydroxide acid leaching residues are jointly used, so that valuable metal elements in the waste battery positive electrode material are synergistically leached, and the use of auxiliary materials is effectively reduced while the efficient metal element leaching rate is kept.

Description

Technical Field

[0001] The present application relates to the field of hydrometallurgical recycling technology, and in particular, to a method for recycling positive electrode materials of waste batteries. Background Art

[0002] With the rapid development of the new energy vehicle industry, the use of new energy vehicles has continued to rise, which has led to a simultaneous increase in the demand for power batteries, but at the same time, the amount of scrapped batteries has also increased sharply. Therefore, it is crucial to develop the waste battery recycling industry, which can not only effectively reduce environmental pollution, but also provide recycled raw materials for the battery manufacturing industry by recycling valuable metal elements such as lithium, nickel, cobalt, manganese, copper, and aluminum from waste batteries, thereby reducing dependence on primary resources. Therefore, it is necessary to recycle and reuse waste batteries.

[0003] It should be noted that the above statements are only used to provide background technical information related to the present application and do not necessarily constitute prior art. Summary of the invention

[0004] In a first aspect of the present application, the present application provides a method for recycling anode materials of waste batteries, comprising: mixing the cathode materials of waste batteries with a sulfuric acid solution to obtain a slurry, wherein the cathode materials of waste batteries include Ni 3+ 、Co 3+ , Mn 3+ at least one of; mixing the slurry with cobalt hydroxide acid leaching residue, and performing a first leaching reaction to obtain a first leachate and a first leaching residue, wherein the cobalt hydroxide acid leaching residue includes cobalt sulfide; mixing the first leachate with iron powder, and performing a second leaching reaction to obtain a second leachate and a second leaching residue, wherein the first leachate includes copper ions; mixing the second leachate with nickel cobalt hydroxide acid leaching residue, and performing a third leaching reaction to obtain a recovered solution and a third leaching residue, wherein the nickel cobalt hydroxide acid leaching residue includes at least one of MnO2, Mn3O4, and MnO(OH).

[0005] This application utilizes the reducibility of cobalt hydroxide acid leaching residue to make Ni 3+ 、Co 3+ or Mn 3+ The reaction generates free Ni 2+ 、Co 2 + or Mn 2+ , so that the acid-insoluble cobalt sulfide generates free Co 2+ , so that the valuable metal elements in the waste battery positive electrode material and cobalt hydroxide acid leaching residue are leached out; then the iron powder and copper ions react to generate metallic copper precipitate and Fe 2+, so that the copper element is separated from the reaction system; then the oxidizing property of the nickel-cobalt hydroxide acid leaching residue is used to separate the Fe 2+ The reaction generates Fe 3+ , so that the acid-insoluble MnO2, Mn3O4 or MnO(OH) generates free Mn 2+ , then Fe 3+ The iron hydroxide precipitate is formed, so that the iron element can be separated from the recovered liquid, and the valuable metal elements in the nickel cobalt hydroxide acid leaching residue can be leached into the recovered liquid. Therefore, the application uses the cobalt hydroxide acid leaching residue and the nickel cobalt hydroxide acid leaching residue in combination, which can make the valuable metal elements in the positive electrode material of the waste battery leached synergistically, while maintaining the high efficiency of the metal element leaching rate, effectively reducing the use of auxiliary materials and reducing the production cost.

[0006] In some embodiments, the copper ions include copper ions in the positive electrode material of the waste battery and / or copper ions in the cobalt hydroxide acid leaching residue. Thus, the iron powder and the copper ions react to generate metallic copper precipitate and Fe 2+ , Fe 2+ It can react with the subsequently added nickel-cobalt hydroxide acid leaching residue, and the metallic copper can be separated from the reaction system.

[0007] In some embodiments, the above method further comprises: mixing the recovery liquid and sulfide salt to perform copper precipitation reaction to obtain pure recovery liquid and fourth leaching residue, thereby further removing residual copper ions in the reaction system.

[0008] In some embodiments, the fourth leaching residue includes copper, and the copper precipitation reaction satisfies at least one of the following conditions: the sulfide salt includes at least one of sodium sulfide, potassium sulfide, and ammonium sulfide; the molar ratio of the sulfide salt to the copper element in the recovered liquid is (1-3):1; the reaction temperature of the copper precipitation reaction is 65°C-95°C; the reaction time of the copper precipitation reaction is 1h-4h. Therefore, by selecting the appropriate type of sulfide salt, the molar ratio of the sulfide salt to the copper element in the recovered liquid, the reaction temperature, and the reaction time, Cu can be efficiently leached. 2+ Converted into copper sulfide precipitate.

[0009] In some embodiments, the step of mixing the waste battery positive electrode material and the sulfuric acid solution satisfies at least one of the following conditions: the mass ratio of the sulfuric acid solution to the waste battery positive electrode material is (2-10):1; the molar concentration of the sulfuric acid solution is 1 mol / L-5 mol / L. Thus, by selecting a suitable mass ratio of the sulfuric acid solution to the waste battery positive electrode material and the molar concentration of the sulfuric acid solution, the waste battery positive electrode material can be fully contacted with the sulfuric acid solution to promote the subsequent reduction reaction of the cobalt hydroxide acid leaching residue.

[0010] In some embodiments, the first leaching reaction satisfies at least one of the following conditions: the leaching temperature of the first leaching reaction is 40°C-95°C; the leaching time of the first leaching reaction is 4h-24h; the mass ratio of the cobalt hydroxide acid leaching residue to the waste battery positive electrode material is (0.05-0.25): 1. Therefore, the appropriate leaching temperature, leaching time and mass ratio of the cobalt hydroxide acid leaching residue to the waste battery positive electrode material are selected to make the cobalt hydroxide acid leaching residue and the waste battery positive electrode material fully react and improve the leaching rate of valuable metals.

[0011] In some embodiments, the second leaching reaction satisfies at least one of the following conditions: the particle size of the iron powder is 100 μm-250 μm; the molar ratio of the iron powder to the copper ion is (1-2.5):1. Thus, by selecting an appropriate iron powder particle size and a molar ratio of the iron powder to the copper ion, Cu can be efficiently leached. 2+ Converted into metallic copper precipitate, thereby improving the recovery rate of copper element.

[0012] In some embodiments, the third leaching reaction satisfies at least one of the following conditions: the leaching temperature of the third leaching reaction is 85°C-98°C; the leaching time of the third leaching reaction is 1h-6h; the pH of the third leaching solution is 4.0-5.5; the mass ratio of iron ions in the second leaching solution to the nickel cobalt hydroxide acid leaching residue is (1-2):1. Therefore, by selecting appropriate leaching temperature, leaching time, and mass ratio of iron ions to nickel cobalt hydroxide acid leaching residue, Fe 2+ Converted to Fe 3+ ; Select the appropriate pH to make Fe 3+ The iron hydroxide precipitate is formed, thereby making it possible to separate the iron element from the reaction system.

[0013] In some embodiments, the recovery solution includes Ni 2+ 、Co 2+ , Mn 2+ Thus, the recovered liquid can be reused.

[0014] In some embodiments, the first leaching residue includes acid-insoluble impurities, thereby the acid-insoluble impurities can be separated from the reaction system.

[0015] In some embodiments, the second leaching residue includes metallic copper, thereby the copper element can be separated from the reaction system.

[0016] In some embodiments, the third leached residue includes iron, so that the iron can be separated from the reaction system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0018] Figure 1 It is a schematic diagram of the process flow of a method for recycling positive electrode materials of waste batteries in one embodiment of the present application. DETAILED DESCRIPTION

[0019] Hereinafter, the method for recycling the positive electrode material of used batteries of the present application is specifically disclosed in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0020] " Scope " disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be to include end values ​​or not include end values, and can be combined arbitrarily, that is, any lower limit can form a scope with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for a particular parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 listed, and if the maximum range values ​​3,4 and 5 are listed, the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0021] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0022] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0023] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application; unless otherwise specified, the numerical values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the embodiments of this application).

[0024] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. "First feature" and "second feature" may include one or more of the features.

[0025] In the description of the present application, "A and / or B" may include the case of A alone, the case of B alone, or any of the cases of A and B, where A and B are only used for examples and may be any technical feature connected by "and / or" in the present application.

[0026] The positive electrode materials of waste batteries contain valuable metal elements such as lithium, nickel, cobalt, manganese, copper, and aluminum. The extraction of these metal elements usually adopts the normal pressure acid leaching process. The normal pressure acid leaching process uses inorganic acids such as sulfuric acid as leaching agents, and combines hydrogen peroxide or sodium sulfite as reducing agents, which can effectively leach the metal elements in the positive electrode materials, laying the foundation for the subsequent separation and purification of the metal elements. However, the normal pressure acid leaching process has some limitations in practical applications. For example, in order to ensure the leaching rate of metal elements, a large amount of reducing agent is consumed in the process, resulting in high production costs, and hydrogen peroxide itself is volatile, which further increases the use of auxiliary materials. Therefore, it is urgent to develop a new method for recycling the positive electrode materials of waste batteries, while maintaining an efficient metal element leaching rate, reducing the consumption of auxiliary materials such as reducing agents.

[0027] In the first aspect of the present application, the present application provides a method for recycling the positive electrode material of waste batteries, referring to Figure 1 , the method comprising:

[0028] S100, mixing the waste battery positive electrode material and the sulfuric acid solution to obtain a slurry.

[0029] In some embodiments, waste batteries are mechanically disassembled, crushed, and classified to obtain waste battery positive electrode materials.

[0030] In some embodiments, the spent battery positive electrode material includes Ni 3+ 、Co 3+ , Mn 3+ At least one of .

[0031] In some embodiments, the waste battery positive electrode material further includes copper. Specifically, the copper element exists in the form of copper oxide and / or metallic copper. Thus, after the waste battery positive electrode material is mixed with the sulfuric acid solution, the slurry includes Cu 2+ .

[0032] In some embodiments, the waste battery positive electrode material further includes at least one of aluminum and iron. Specifically, the aluminum element exists in the form of aluminum oxide and / or metallic aluminum, and the iron element exists in the form of iron oxide. 3+ , Fe 2+ 、Al 3+ At least one of .

[0033] In some embodiments, the step of mixing the waste battery positive electrode material and the sulfuric acid solution satisfies at least one of the following conditions: the mass ratio of the sulfuric acid solution to the waste battery positive electrode material is (2-10):1; the molar concentration of the sulfuric acid solution is 1mol / L-5mol / L. Thus, by selecting an appropriate mass ratio of the sulfuric acid solution to the waste battery positive electrode material and the molar concentration of the sulfuric acid solution, the waste battery positive electrode material can be fully contacted with the sulfuric acid solution; when the waste battery positive electrode material includes copper oxide, metallic copper, aluminum oxide, iron oxide, etc., it can react quickly to generate Fe 3+ , Fe 2+ , Cu 2+ or Al 3+ .

[0034] As an example, the mass ratio of sulfuric acid solution to waste battery positive electrode material can be 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1.

[0035] As an example, the molar concentration of the sulfuric acid solution may be 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L or 5 mol / L.

[0036] As an example, the step of mixing the waste battery positive electrode material and the sulfuric acid solution meets the following conditions: the mass ratio of the sulfuric acid solution to the waste battery positive electrode material is (2-10):1; the molar concentration of the sulfuric acid solution is 1 mol / L-5 mol / L.

[0037] S200, mixing the slurry and the cobalt hydroxide acid leaching residue, and performing a first leaching reaction to obtain a first leaching solution and a first leaching residue.

[0038] Crude cobalt hydroxide is one of the main sources of cobalt in ternary batteries. After acid leaching, crude cobalt hydroxide produces cobalt ions and cobalt hydroxide acid leaching residue. The cobalt ions are separated and recovered, while the cobalt hydroxide acid leaching residue, as a hazardous solid waste residue, is currently mainly treated by slag storage, which not only pollutes the environment, but also causes the loss of valuable metal cobalt. Cobalt hydroxide acid leaching residue mainly includes cobalt sulfide (CoS), or a small amount of copper sulfide (CuS), and other impurities insoluble in acid.

[0039] In some embodiments, the cobalt hydroxide acid leaching residue includes CoS. In the present application, the cobalt hydroxide acid leaching residue is used to react with the positive electrode material of the waste battery to make Ni 3+ 、Co 3+ or Mn 3+ The reaction generates free Ni 2+ 、Co 2+ or Mn 2+ , which converts acid-insoluble CoS into free Co 2+ Thus, the first leaching solution contains valuable metal ions generated from the waste battery positive electrode material and the cobalt hydroxide acid leaching residue respectively, and the first leaching solution can participate in subsequent reactions to separate and purify the valuable metal ions.

[0040] As an example, the cathode material of a used battery satisfies the chemical formula LiNi x Co y Mn (1-x-y) O2, where x and y are independently atomic percentages, and x and y simultaneously satisfy: 0<x+y<1, 0<x<1, 0<y<1. Therefore, the reaction equation of waste battery positive electrode material and cobalt hydroxide acid leaching residue is as follows:

[0041] 8LiNi x Co y Mn (1-x-y) O2+CoS+12H2SO4→

[0042] 4Li2SO4+8xNiSO4+(8y+1)CoSO4+8(1-xy)MnSO4+12H2O.

[0043] In some embodiments, the cobalt hydroxide acid leaching residue also includes CuS. 3+ 、Co 3+ or Mn 3+ The reaction generates free Ni 2+ 、Co 2+ or Mn 2+ , which converts the acid-insoluble CuS into free Cu 2+ As an example, the reaction equation of waste battery positive electrode material and cobalt hydroxide acid leaching residue is as follows:

[0044] 8LiNi x CoyMn (1-x-y) O2+CuS+12H2SO4→

[0045] 4Li2SO4+8xNiSO4+8yCoSO4+8(1-xy)MnSO4+CuSO4+12H2O.

[0046] In some embodiments, the first leaching reaction satisfies at least one of the following conditions: the leaching temperature of the first leaching reaction is 40°C-95°C; the leaching time of the first leaching reaction is 4h-24h; the mass ratio of cobalt hydroxide acid leaching residue to the waste battery positive electrode material is (0.05-0.25): 1. Therefore, the appropriate leaching temperature, leaching time and mass ratio of cobalt hydroxide acid leaching residue to waste battery positive electrode material are selected to make the cobalt hydroxide acid leaching residue and the waste battery positive electrode material fully react and improve the leaching rate of valuable metals.

[0047] As an example, the leaching temperature of the first leaching reaction may be 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or 95°C.

[0048] As an example, the leaching time of the first leaching reaction may be 4 h, 8 h, 12 h, 16 h, 20 h or 24 h.

[0049] As an example, the mass ratio of cobalt hydroxide acid leaching residue to waste battery positive electrode material can be 0.05:1, 0.1:1, 0.15:1, 0.2:1 or 0.25:1.

[0050] As an example, the first leaching reaction satisfies the following conditions: the leaching temperature of the first leaching reaction is 40°C-95°C; the leaching time of the first leaching reaction is 4h-24h; the mass ratio of cobalt hydroxide acid leaching residue to waste battery positive electrode material is (0.05-0.25):1.

[0051] In some embodiments, the first leached residue includes impurities insoluble in acid. Thus, valuable metal elements in the waste battery positive electrode material and cobalt hydroxide acid leached residue are leached into the first leaching solution, and impurities insoluble in acid are separated from the reaction system.

[0052] S300, mixing the first leaching solution and iron powder, and performing a second leaching reaction to obtain a second leaching solution and a second leaching residue.

[0053] In some embodiments, the first leachate includes Cu 2+ . Iron powder and Cu 2+ The reaction generates metallic copper precipitate and Fe 2+ Therefore, the second leachate includes Fe 2+, and the second leaching slag metallic copper can be separated from the second leaching solution.

[0054] Specifically, the Cu in the first leaching solution 2+ Derived from Cu in the slurry in step S100 2+ , and / or, Cu of the first leachate 2 + Cu is generated from the reaction of CuS in step S200. 2+ .

[0055] In some embodiments, the second leaching reaction satisfies at least one of the following conditions: the particle size of the iron powder is 100 μm-250 μm; the molar ratio of the iron powder to the copper ion is (1-2.5):1. Thus, by selecting an appropriate iron powder particle size and a molar ratio of the iron powder to the copper ion, Cu can be efficiently leached. 2+ Converted into metallic copper precipitate, thereby improving the recovery rate of copper element.

[0056] As an example, the particle size of the iron powder may be 100 μm, 150 μm, 200 μm or 250 μm.

[0057] As an example, the molar ratio of iron powder to copper ions is 1:1, 1.5:1, 2:1 or 2.5:1.

[0058] As an example, the second leaching reaction satisfies the following conditions: the particle size of the iron powder is 100 μm-250 μm; the molar ratio of the iron powder to the copper ion is (1-2.5):1.

[0059] S400, mixing the second leaching solution and the nickel cobalt hydroxide acid leaching residue, and performing a third leaching reaction to obtain a recovered solution and a third leaching residue.

[0060] Crude nickel cobalt hydroxide is one of the main sources of nickel in ternary batteries. After acid leaching, crude nickel cobalt hydroxide produces cobalt ions, nickel ions and nickel cobalt hydroxide acid leaching residue. Cobalt ions and nickel ions are separated and recovered, while nickel cobalt hydroxide acid leaching residue is a hazardous solid waste residue, which is currently mainly treated by slag storage, which not only pollutes the environment, but also causes the loss of valuable metals.

[0061] In some embodiments, the nickel cobalt hydroxide acid leaching residue mainly includes at least one of MnO2, Mn3O4, and MnO(OH). In the present application, the oxidizing property of the nickel cobalt hydroxide acid leaching residue is utilized to make Fe 2+ The reaction generates Fe 3+ , so that the acid-insoluble MnO2, Mn3O4 or MnO(OH) generates free Mn 2+ .

[0062] As an example, when the nickel cobalt hydroxide acid leaching residue includes MnO2, the reaction equation of the nickel cobalt hydroxide acid leaching residue and the second leaching solution is as follows: 2FeSO4+MnO2+2H2SO4→Fe2(SO4)3+MnSO4+2H2O.

[0063] As an example, when the nickel cobalt hydroxide acid leaching residue includes Mn3O4, the reaction equation of the nickel cobalt hydroxide acid leaching residue and the second leachate is as follows: 2FeSO4+Mn3O4+4H2SO4→Fe2(SO4)3+3MnSO4+4H2O.

[0064] As an example, when the nickel cobalt hydroxide acid leaching residue includes MnO(OH), the reaction equation of the nickel cobalt hydroxide acid leaching residue and the second leachate is as follows: 2FeSO4+2MnO(OH)+3H2SO4→Fe2(SO4)3+2MnSO4+4H2O.

[0065] In some embodiments, the third leaching reaction satisfies at least one of the following conditions: the leaching temperature of the third leaching reaction is 85°C-98°C; the leaching time of the third leaching reaction is 1h-6h; the pH of the third leaching solution is 4.0-5.5; the mass ratio of iron ions in the second leaching solution to nickel cobalt hydroxide acid leaching residue is (1-2):1. Selecting appropriate leaching temperature, leaching time, and mass ratio of iron ions to nickel cobalt hydroxide acid leaching residue can efficiently remove Fe 2+ Converted to Fe 3+ ; Select the appropriate pH to make Fe 3+ The iron hydroxide precipitate is formed, so that the third leaching residue iron hydroxide can be separated from the recovered liquid. Thus, the iron element added in step S300 or the iron element in the positive electrode material of the waste battery can be removed.

[0066] As an example, the leaching temperature of the third leaching reaction may be 85°C, 88°C, 92°C, 94°C, 96°C or 98°C.

[0067] As an example, the leaching time of the third leaching reaction may be 1 h, 2 h, 3 h, 4 h, 5 h or 6 h.

[0068] As an example, the pH of the third leachate may be 4.0, 4.5, 5.0 or 5.5.

[0069] As an example, the mass ratio of iron ions in the second leachate to nickel cobalt hydroxide acid leaching residue can be 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1 or 2:1.

[0070] As an example, the third leaching reaction satisfies the following conditions: the leaching temperature of the third leaching reaction is 85°C-98°C; the leaching time of the third leaching reaction is 1h-6h; the pH of the third leachate is 4.0-5.5; the mass ratio of iron ions in the second leachate to nickel cobalt hydroxide acid leaching residue is (1-2):1.

[0071] In some embodiments, when the waste battery positive electrode material includes aluminum, Al 3+ Aluminum hydroxide precipitation is formed, so that the third leaching residue aluminum hydroxide can be separated from the recovered liquid. Thus, the aluminum element in the positive electrode material of the waste battery can be removed.

[0072] In order to further remove the copper element in the reaction system, in some embodiments, the above method further comprises: mixing the recovered liquid with a sulfide salt to perform a copper precipitation reaction to obtain a pure recovered liquid and a fourth leaching residue. 2+ When sulfide salt and Cu 2+ The copper precipitation reaction occurs to generate copper sulfide precipitation to obtain a pure recovery liquid. The pure recovery liquid includes Ni 2+ 、Co 2+ , Mn 2+ In addition, the fourth leaching residue copper sulfide precipitate can also return to step S200 to participate in the reaction again.

[0073] In some embodiments, the copper precipitation reaction satisfies at least one of the following conditions: the sulfide salt includes at least one of sodium sulfide, potassium sulfide, and ammonium sulfide; the molar ratio of the sulfide salt to the copper element in the recovery liquid is (1-3):1; the reaction temperature of the copper precipitation reaction is 65°C-95°C; the reaction time of the copper precipitation reaction is 1h-4h. Therefore, by selecting the appropriate type of sulfide salt, the molar ratio of the sulfide salt to the copper element in the recovery liquid, the reaction temperature, and the reaction time, Cu can be efficiently converted to Cu. 2+ Converted into copper sulfide precipitate.

[0074] As an example, the molar ratio of the sulfide salt to the copper element in the recovered liquid can be 1:1, 1.5:1, 2:1, 2.5:1 or 3:1.

[0075] As an example, the reaction temperature of the copper deposition reaction may be 65°C, 70°C, 75°C, 80°C, 85°C, 90°C or 95°C.

[0076] As an example, the reaction time of the copper plating reaction may be 1 h, 2 h, 3 h or 4 h.

[0077] As an example, the copper precipitation reaction satisfies the following conditions: the sulfide salt includes at least one of sodium sulfide, potassium sulfide, and ammonium sulfide; the molar ratio of the sulfide salt to the copper element in the recovery liquid is (1-3):1; the reaction temperature of the copper precipitation reaction is 65°C-95°C; the reaction time of the copper precipitation reaction is 1h-4h.

[0078] In summary, the cathode material of the waste battery is first mixed with a sulfuric acid solution to make the copper, aluminum or iron in the cathode material of the waste battery generate free Fe 3+ , Fe 2+ 、Al 3+ Cu 2+ ; Then, the reducibility of cobalt hydroxide acid leaching residue is used to make Ni 3+ 、Co 3+ or Mn 3+ The reaction generates free Ni 2+ 、Co 2+ or Mn 2+ , so that the acid-insoluble CoS or CuS generates free Co 2+ Cu 2+ , so that the valuable metal elements in the waste battery positive electrode material and cobalt hydroxide acid leaching residue are leached out; then the iron powder and Cu 2+ The reaction generates metallic copper precipitate and Fe 2+ , so that the copper element is separated from the reaction system; then the oxidizing property of the nickel-cobalt hydroxide acid leaching residue is used to separate the Fe 2+ The reaction generates Fe 3+ , so that the acid-insoluble MnO2, Mn3O4 or MnO(OH) generates free Mn 2 + , then Fe 3+ The iron hydroxide precipitate is formed, so that the iron element can be separated from the recovered liquid. In addition, when the recovered liquid still has Cu 2+ When sulfide salt and Cu 2+ A copper precipitation reaction occurs to generate copper sulfide precipitation to obtain a pure recovery liquid. Therefore, the application uses cobalt hydroxide acid leaching residue and nickel hydroxide cobalt acid leaching residue in combination, which can make the valuable metal elements in the positive electrode material of waste batteries synergistically leached, while maintaining a high efficiency of metal element leaching rate, effectively reducing the use of auxiliary materials and reducing production costs.

[0079] The scheme of the present application is described below by specific examples. It should be noted that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If no specific technology or conditions are specified in the examples, the technology or conditions described in the literature in this area or the product instructions are used. The reagents or instruments used are not specified by the manufacturer, and are all conventional products that can be obtained commercially.

[0080] Example 1

[0081] S100, mixing the waste battery positive electrode material and the sulfuric acid solution, adding the mixture into a reactor and stirring, so as to obtain a slurry; wherein the molar concentration of the sulfuric acid solution is 4 mol / L, the mass ratio of the sulfuric acid solution to the waste battery positive electrode material is 5:1, and the contents of the elements contained in the waste battery positive electrode material are shown in Table 1;

[0082] S200, adding cobalt hydroxide acid leaching residue (the content of elements contained in the cobalt hydroxide acid leaching residue is shown in Table 1) to the slurry, and performing a first leaching reaction to obtain a first leachate and a first leaching residue, wherein the first leaching residue includes impurities insoluble in acid; wherein the leaching temperature of the first leaching reaction is 80° C., the leaching time of the first leaching reaction is 12 h, and the mass ratio of the cobalt hydroxide acid leaching residue to the waste battery positive electrode material is 0.15:1;

[0083] S300, adding iron powder to the first leachate to perform a second leaching reaction, and after the reaction is completed, filtering to obtain a second leachate and a second leach residue, wherein the second leach residue includes metallic copper; wherein the particle size of the iron powder is 150 μm, and the molar ratio of the iron powder to the copper ions in the first leachate is 2:1;

[0084] S400, adding nickel cobalt hydroxide acid leaching residue (the content of elements contained in the nickel cobalt hydroxide acid leaching residue is shown in Table 1) to the second leachate, and performing a third leaching reaction, wherein the leaching temperature of the third leaching reaction is 95° C., the leaching time of the third leaching reaction is 4 hours, the pH of the third leaching solution is 5.0, and the mass ratio of iron ions in the second leaching solution to nickel cobalt hydroxide acid leaching residue is 1:1; after the reaction is completed, a recovered liquid and a third leaching residue are obtained; the third leaching residue is a mixture of iron hydroxide and aluminum hydroxide layers;

[0085] S500, adding sodium sulfide to the recovered liquid to carry out a copper precipitation reaction to obtain a pure recovered liquid and a fourth leaching residue copper sulfide; wherein the molar ratio of sodium sulfide to the copper element in the recovered liquid is 2:1, the reaction temperature of the copper precipitation reaction is 85° C., and the reaction time of the copper precipitation reaction is 2 hours.

[0086] Table 1. Content of each raw material element

[0087]

[0088] The difference between Example 2 and Example 1 is that the mass ratio of cobalt hydroxide acid leaching residue to waste battery positive electrode material is 0.05:1.

[0089] The difference between Example 3 and Example 1 is that the mass ratio of cobalt hydroxide acid leaching residue to waste battery positive electrode material is 0.25:1.

[0090] The difference between Example 4 and Example 1 is that the mass ratio of iron ions in the second leachate to nickel cobalt hydroxide acid leaching residue is 1.5:1.

[0091] The difference between Example 5 and Example 1 is that the mass ratio of iron ions in the second leachate to nickel cobalt hydroxide acid leaching residue is 2:1.

[0092] The difference between Comparative Example 1 and Example 1 is that an equal amount of sodium sulfite replaces the cobalt hydroxide acid leaching residue.

[0093] The difference between Comparative Example 2 and Example 1 is that an equal amount of hydrogen peroxide replaces the nickel cobalt hydroxide acid leaching residue.

[0094] The difference between Comparative Example 3 and Example 1 is that an equal amount of sodium sulfite replaces the cobalt hydroxide acid leaching residue, and an equal amount of hydrogen peroxide replaces the nickel cobalt hydroxide acid leaching residue.

[0095] The difference between Comparative Example 4 and Example 1 is that an equal amount of hydrogen peroxide replaces the cobalt hydroxide acid leaching residue, and an equal amount of hydrogen peroxide replaces the nickel cobalt hydroxide acid leaching residue. Among them, hydrogen peroxide can act as a reducing agent to react with the positive electrode material of the waste battery, and can also act as an oxidant to react with Fe 2+ The reaction generates Fe 3+ .

[0096] The difference between Comparative Example 5 and Example 1 is that no cobalt hydroxide acid leaching residue is added.

[0097] The difference between Comparative Example 6 and Example 1 is that no nickel hydroxide cobalt acid leaching residue is added.

[0098] The contents of the various elements in the pure recovered liquids obtained in Examples 1-5 and Comparative Examples 1-5 were tested respectively, and the leaching rates of nickel, cobalt, manganese and lithium, and the removal rates of iron, aluminum and copper in each Example and each Comparative Example were calculated respectively.

[0099] Leaching rate = metal element content in pure recovery liquid / (metal element content in waste battery positive electrode material + metal element content in cobalt hydroxide acid leaching residue + metal element content in nickel cobalt hydroxide acid leaching residue) × 100%.

[0100] Removal rate = 1-[metal element content in pure recovery liquid / (metal element content in waste battery positive electrode material + metal element content in cobalt hydroxide acid leaching residue + metal element content in nickel cobalt hydroxide acid leaching residue) × 100%].

[0101] The experimental results are shown in Table 2.

[0102] Table 2

[0103]

[0104] As shown in Table 2, Examples 1-5 use cobalt hydroxide acid leaching residue and nickel cobalt hydroxide acid leaching residue in combination, which can make the valuable metal elements in the positive electrode material of the waste battery synergistically leached. Compared with Comparative Examples 1-4 using hydrogen peroxide or sodium sulfite, the present application can still maintain efficient leaching rates of Ni, Co, Mn, and Li elements, as well as efficient removal rates of Fe, Al, and Cu elements. In addition, cobalt hydroxide acid leaching residue and nickel cobalt hydroxide acid leaching residue can replace hydrogen peroxide or sodium sulfite, which can not only reduce the use of auxiliary materials, but also reuse hazardous solid waste residues.

[0105] In Comparative Example 5, no hazardous solid waste residue, cobalt hydroxide acid leaching residue, is added, so the high-valent valuable metal elements in the positive electrode material of the waste battery cannot generate free Ni 2+ 、Co 2+ , Mn 2+ , Li 2+ , resulting in the Ni in the pure recovery liquid 2+ 、Co 2+ , Mn 2+ , Li 2 + The content is low, resulting in the leaching rates of Ni, Co, Mn and Li being lower than those of Examples 1-5.

[0106] Comparative Example 6: No hazardous solid waste residue was added to the nickel-cobalt hydroxide acid leaching residue. The Fe 2+ Unable to react to generate Fe 3+ , which results in the inability to generate iron hydroxide precipitation to separate the iron element from the reaction system. Therefore, the content of iron element in the pure recovered liquid is relatively high, and the removal rate of iron element is lower than the removal rate of Example 1-5.

[0107] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for recycling positive electrode materials of waste batteries, characterized in that: include: The waste battery positive electrode material and the sulfuric acid solution are mixed to obtain a slurry, wherein the waste battery positive electrode material includes Ni 3+ 、Co 3+ , Mn 3+ At least one of; The slurry is mixed with cobalt hydroxide acid leaching residue to perform a first leaching reaction to obtain a first leachate and a first leaching residue, wherein the cobalt hydroxide acid leaching residue includes cobalt sulfide; The first leachate and iron powder are mixed to perform a second leaching reaction to obtain a second leachate and a second leach residue, wherein the first leachate includes copper ions; The second leaching solution and the nickel cobalt hydroxide acid leaching residue are mixed to carry out a third leaching reaction to obtain a recovered solution and a third leaching residue, wherein the nickel cobalt hydroxide acid leaching residue includes at least one of MnO2, Mn3O4, and MnO(OH).

2. The method according to claim 1, characterized in that The copper ions include the copper ions in the positive electrode material of the waste battery and / or the copper ions in the cobalt hydroxide acid leaching residue.

3. The method according to claim 2, characterized in that Further including: The recovered liquid is mixed with sulfide salt to carry out copper precipitation reaction to obtain pure recovered liquid and fourth leaching residue.

4. The method according to claim 3, characterized in that The fourth leaching residue includes copper element, and the copper precipitation reaction satisfies at least one of the following conditions: The sulfide salt includes at least one of sodium sulfide, potassium sulfide and ammonium sulfide; The molar ratio of the sulfide salt to the copper element in the recovered liquid is (1-3):1; The reaction temperature of the copper deposition reaction is 65°C-95°C; The reaction time of the copper deposition reaction is 1h-4h.

5. The method according to any one of claims 1 to 4, characterized in that: The step of mixing the waste battery positive electrode material and the sulfuric acid solution satisfies at least one of the following conditions: The mass ratio of the sulfuric acid solution to the positive electrode material of the waste battery is (2-10):1; The molar concentration of the sulfuric acid solution is 1 mol / L-5 mol / L.

6. The method according to any one of claims 1 to 4, characterized in that: The first leaching reaction satisfies at least one of the following conditions: The leaching temperature of the first leaching reaction is 40°C-95°C; The leaching time of the first leaching reaction is 4h-24h; The mass ratio of the cobalt hydroxide acid leaching residue to the waste battery positive electrode material is (0.05-0.25):

1.

7. The method according to any one of claims 1 to 4, characterized in that: The second leaching reaction satisfies at least one of the following conditions: The particle size of the iron powder is 100 μm-250 μm; The molar ratio of the iron powder to the copper ions is (1-2.5):

1.

8. The method according to any one of claims 1 to 4, characterized in that: The third leaching reaction satisfies at least one of the following conditions: The leaching temperature of the third leaching reaction is 85°C-98°C; The leaching time of the third leaching reaction is 1h-6h; The pH of the third leachate is 4.0-5.5; The mass ratio of iron ions in the second leachate to the nickel-cobalt hydroxide acid leaching residue is (1-2):

1.

9. The method according to any one of claims 1 to 4, characterized in that: The recovery liquid includes Ni 2+ 、Co 2+ , Mn 2+ At least one of .

10. The method according to any one of claims 1 to 4, characterized in that: The first leaching residue includes impurities insoluble in acid; and / or, The second leaching residue includes metallic copper; and / or, The third leaching residue includes iron.

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